Arguments
Europe is parched, in a sign of times to come
Posted on 9 September 2015 by John Abraham
Europe has undergone a severe drought this summer, the worst in over a decade. Temperatures have been high across the continent, and have combined with low rainfalls. This drought, like the one in 2012 in the United States, are a sign of what our future holds in a warming world.
As humans emit greenhouse gases, the world warms. We already know that. But a warming world is also host to other changes. Among the most important changes are those to the water cycle. Scientists refer to this as the hydrological cycle – basically changes to the storage of water in the soil and underground, the evaporation of water into the atmosphere, and the subsequent rainfall and runoff that occurs.
A warmer atmosphere can hold more moisture, as people know through the personal experience of high humidity in warm months. Changes to humidity have been measured over the past decades and confirm our expectations. These changes lead to increased rainfall.
At the same time, higher temperatures accelerate evaporation, which dries out the soil and plants and can create drought conditions.
We see then that competing factors are in play. On the one hand, we expect there to be more intense rainfall. On the other hand, we expect more drying. Which process wins depends on where you live. The prevailing view is that areas which are currently wet will become wetter. Areas that are currently dry will become drier. Finally, rainfall will occur in heavier doses.
A recent report has been released about current conditions in Europe and in particular, on the 2015 heat wave and drought. The organization (European Drought Observatory) has an online report which is easy to obtain and read here. They report that very hot weather in Europe during June and July 2015 affected France, Belgium, The Netherlands, Luxembourg, Germany, Hungary, the Czech Republic, Italy and Spain.
High temperatures combined with low rainfall have created very dry conditions. Not only were temperatures high, but they remained high for a long time, particularly in parts of Spain. The images below show which regions have been hotter than normal (yellow, orange, and red colors) as well as which areas have been drier than normal (yellow, orange, and red). Both regions extend across a wide swath of Europe.
Warmer and colder regions than normal. Source: European Drought Observatory.
Drier soils than normal. Source: European Drought Observatory.
Countries are dealing with the water shortage by placing restrictions on water use, especially in the agricultural sector. However, the lack of water is also affecting public water supply, river transportation, natural habitats, plants, animals, and insects, and power supply.
But it could get worse. Long-range weather forecasts are for continued warm and dry conditions through September. Future rain is particularly important for vegetation. As the report states,
This article is making much of very little. As has been the case for the last 10 years, I was in France in June and July and where I was it was warm to hot but temperatures were not abnormally high and there was some rain. But personal experience of the weather aside this piece by John Abraham starts with the comment the worst drought in over a decade. Surely this is just weather as climate has to be considered in periods of not less than 30 years. Or am I mistaken and 10 years is now the new norm? On the other hand the weather in the UK this year was cool and damp with rainfall slightly above the norm so is this what we can expect in the UK with climzte change?
Paul Homewood in Not a lot of people know that said "It all rather goes to show just how variable British weather is in summer." I think that comment applies equally to Europe
Perhaps more significantly Chief Scientist at the Met Office Julia Slgo commenting on the poor UK summer had this to say (http://tinyurl.com/omcjc9f):
"If we look beyond our shores there have been some big changes in the global climate this year. El Niño is in full flight, disturbing weather patterns around the world. The low pressure that has dominated our weather is part of a pattern of waves in the jet stream around the world that has brought crippling heat waves to places like Poland and Japan. And, looking back over past El Niños, you could have expected that a more unsettled summer might be on the cards for the UK. Closer to home the North Atlantic is more than 2 degrees colder than normal. It seems quite likely that the unusually cold North Atlantic has strengthened and pushed our jet stream south, also contributing to the low pressure systems that have dominated our weather."
So how much has the weather in Europe been affected by El Nino rather than by human induced climate change?
[PS] This is bordering on cheap sloganeering. The article presents drought severity data for Europe not anecdote nor local conditions. Nor claims that the drought itself is climate change. It notes that higher temperatures (that is climate change) will worsen low rainfall conditions. If you wish to contest the drought severity, then present alternative data. I doubt you can contest that warmer temperatures will not worsen drought nor that Europe is getting warmer over 30 years.
That's a fine collection of irrelevancies that you're offering there, ryland. Keep it up. I hope that you'll continue to go to France over the coming decades and report back how it seems okay to you. It's invaluable data, I can assure you, and by far the most important part of your post. :-)
ryland @1 asks if the hot, dry weather in Europe this summer may have been an ENSO impact. As can be seen, the June-August impacts of El Nino's do not impact Europe:
Wikipedia says:
So not only is it the wrong season for the drought to be an ENSO impact, but El Nino's lead to wetter weather in Southern Europe, and colder weather in Northern Europe, so that hot, dry weather across both is very unlikely to be an ENSO impact.
ryland also gives an an anecdotal account of his stay in France, but does not mention where in France. As can be seen from the maps, the mediterainian coast (particularly near Monaco) was largely spared the impacts of heat and drought. Nor does he give a precise time period. Anecdotes are poor evidence relative to measured data, but when they are so vague as Ryland's they are worthless.
Finally, Ryland draws attention to the fact that the current drought and heatwave is only the worst in over a decade. That is probably because just over a decade ago, Europe suffered the 2003 heatwave, described as " the hottest summer on record in Europe since at least 1540", and of which it is further said:
Since then Europe was hit by a further heatwave in 2010, which also set record temperatures in the areas impacted by the 2003 and 2015 heatwaves, a fact often missed due to the appropriate attention to the astonishing impacts in Russia. The July 2015 heatwave has also broken several temperature records.
So, in the space of 13 years, Europe has been hit by an (approx) 1:500 year heatwave event with two follow up heat waves almost as bad (and much worse in other parts of Europe for one of them). It would be interesting to see precise statistics, but a succession of such previously rare or unprecedented events in so short a space of time is an issue about climate change. It is not just a matter of weather. John Abraham may reasonably be criticized for not giving sufficient note to the fact that the 2015 event is the worst in just over a decade; but the criticism is that he did not set this heat wave in the context of other recent events - not the spurious argument by Ryland.
On the one hand, some argue that the so-called Little Ice Age was localized to Europe and therefore average global temperatures and conditions during that period cannot be extrrapolated. On the other hand, one summer of drought in Europe is a harbinger of global conditions for the century to come?
Exactly how are these two perspectives be reconciled?
To the Moderator: The title of the article is, "Europe is parched, in a sign of times to come." in addition, the first paragraph states, "This drought, like the one in 2012 in the United States, are a sign of what our future holds in a warming world." Then the artcle ends with a quote from Dr. Jürgen Vogt: "Extreme temperatures and dry conditions as observed this year are likely to increase in frequency and severity over the coming decades..."
Therefore, I think scolding anyone by claiming that this artilce makes no "claims that the drought itself is climate change" is unwarranted and disingenous. In fact, to make such an assertion is to obfuscate the main thrust the of the article, which was not written merely to inform the public about European drought condition pervailing in the summer of 2015 but to tie these conditions to future climate change.
@ Ignaz
"some argue that the so-called Little Ice Age was localized to Europe and therefore average global temperatures and conditions during that period cannot be extrrapolated."
You are comparing apples and pears here. There are multiple proxies for temperature around the world contemporaneous with the Little Ice Age; these indicate that the phenomenon was largely confine to Northern Europe. To 'extrapolate' from what is largely anecdotal evidence anyway (the Thames freezing and so forth) rather than hard tempertaure data, would be simply be to ignore the bulk of the data available from around the world.
The drought indicators for Europe need no extrapolation because we have data on rainfall from all over the planet right now (which obviously was not the case with rainfall or temperatures in the 17th Century).
This article is simply pointing out the statistical fact that periods of low rainfall are becoming more frequent in Europe, and that this is consistent with higher temperatures at these latitudes. If temperatures continue to rise (which they surely will), it is likely that this trend will continue. So this year is indeed a taste of things to come, in that such dry years are likiely to become more and more the norm, rather than the exception.
A paper by Benjamin Lloyd-Hughes and Mark Saunders published in 2002 inthe International Journal of Climatology and examining drought on a pan-European basis (http://tinyurl.com/qcvmyvm) states inter alia
"Drought is a recurrent feature of the European climate that is not restricted to the Mediterranean region: it can occur in high and low rainfall areas and in any season (European Environment Agency, 2001). Large areas of Europe have been affected by drought during the 20th century. Recent severe and prolonged droughts have highlighted Europe’s vulnerability to this natural hazard and alerted the public, governments, and operational agencies to the many socio-economic problems accompanying water shortage and to the need for drought mitigation measures."
"The mean duration of extreme and moderate European drought events, on a time scale of 12 months, is 27 ± 8 months and 21 ± 3 months respectively. There is an indication that the mean duration has shortened during the 20th century".
"For drought, we conclude that the proportion of Europe experiencing extreme and/or moderate drought conditions has changed insignificantly during the 20th century. Decadal trends in drought extent (Figure 6) are apparent, however, with greater pan-European drought incidence in the 1940s, early 1950s, and the 1990s, and lesser drought incidence in the 1910s, 1930s, and 1980s."
A paper by Spinoni et al published in 2015 in the Journal of Hydrology: Regional Studies entitled " The biggest droughtn events in Europe from 1950 to 2012 looked at European drought on a regional basis (http://tinyurl.com/oq6veko) conclude:
We computed time series of the combined indicators for each region and country to determine the twenty-two biggest drought events in 1950–2012. Northern Europe and Russia show the highest drought frequency, duration, and severity in the 1950s and 1960s, where this is for the 1970s in Central Europe and the British Islands, and the 1990s and 2000s for the Mediterranean area and Baltic Republics.
Europe experienced a decrease of drought affected areas until the early 1980s, followed by a small but continuous increase in the last three decades. The North-Eastern regions (ICE, FEN, RUS, and ex-USR) show a decrease, the South-Western ones (IBE, ITA, BLK, and AEG) an increase, and Central and Eastern Europe (FBLX, CEN, EAST, and BLC) act like transition areas showing no clear tendencies. These findings are consistent with the conclusions made by Willems, 2013a and Willems, 2013b that precipitation extremes show oscillatory behaviour over multi-decadal time scales, and that the oscillation phases shift across Europe.
These papers are not entirely in agreement with the assertions of John Abraham